Cytomorphology of Circulating Colorectal Tumor Cells: A Small Case Series

Abstract

Several methodologies exist to enumerate circulating tumor cells (CTCs) from the blood of cancer patients; however, most methodologies lack high-resolution imaging, and thus, little is known about the cytomorphologic features of these cells. In this study of metastatic colorectal cancer patients, we used immunofluorescent staining with fiber-optic array scanning technology to identify CTCs, with subsequent Wright-Giemsa and Papanicolau staining. The CTCs were compared to the corresponding primary and metastatic tumors. The colorectal CTCs showed marked intrapatient pleomorphism. In comparison to the corresponding tissue biopsies, cells from all sites showed similar pleomorphism, demonstrating that colorectal CTCs retain the pleomorphism present in regions of solid growth. They also often retain particular cytomorphologic features present in the patient's primary and/or metastatic tumor tissue. This study provides an initial analysis of the cytomorphologic features of circulating colon cancer cells, providing a foundation for further investigation into the significance and metastatic potential of CTCs.

Cytomorphology of Circulating Tumor Cells and Cell Clusters in Chilean Patients with Colo-Rectal Cancer

“…CTCs maintain the same overall pleomorphism, with variations in size, shape and nuclear:cytoplasmic ratios. This supports the hypothesis that CTCs represent a random sampling of the many phenotypic cell types present in primary and metastatic disease, as proposed by Marrinucci et al (2010), and the presence of CTCs with similar morphology as signet cells argues against that only particular subsets of tumor cells enter the circulation, such as very poorly differentiated "stem cell like" tumor cells, or only visibly dead or apoptotic tumor cells. That there were no differences in the morphology of CTCs in relation with the grade of differentiation of the primary or metastatic tumor, or between primary and secondary CTCs and that in general all were of a more rounded more suggests that in the blood environment without the presence of tissue support the cells take on a more spherical form rather than a columnar form.…”

“…These circulating tumor cells can be detected in the blood of patients with colo-rectal cancer (CRC) before the development of metastasis (Glaves, 1983). Circulating tumor cells (CTCs) have been detected in the peripheral blood of patients with a variety of metastatic solid tumors at varying concentrations using a variety of methods, such as RT-PCR, immunocytochemistry, immunoflorescence and flow cytometry (Jonas et al, 1996: Nagrath et al, 2007: Sastre et al, 2008: Marrinucci et al, 2010. The majority of these cells will die, it has been estimated that fewer than 0.01% of CTCs will implant and form metastasis (Fidler, 1973), and most CTCs are cleared from the circulation within 24 hours (Fidler, 1970).…”

Circulating tumor cell technologies

“…Measurements of the nuclear to cytoplasmic ratio (N/C), which may allow one to infer relative deformability, indicate that CTCs are less deformable than leukocytes; Meng et al reported average N/ C ratios of 0.8 and 0.55 for CTCs and leukocytes, respectively. Similar to size and other morphological features of CTCs, several studies have reported significant variation in N/C (Marrinucci et al, 2007(Marrinucci et al, , 2010. Interestingly, these differences may function as a biomarker to identify more aggressive tumors, as CTCs isolated from castrate-resistant prostate cancer patients were approximately three times more deformable than castrate-sensitive samples as measured by atomic force microscopy (Osmulski et al, 2014).…”

High-throughput size-based rare cell enrichment using microscale vortices

“…Here, the purity of the collected sample was determined from the number cell ratio between cancer and blood cells at the outlet. The ability to concentrate cells of interest in a small volume will enhance the overall throughput of current state-of-the-art image based target cell detection systems 35,43 when the present device is integrated upfront of such systems. Additionally, integrating this system upfront of current cytopathology or immunocytochemistry 44 will expedite diagnostic and/or prognostic processes as the volume/area to be scanned/examined would be considerably reduced compared to current methods.…”